Epilepsy is a disease of the brain characterised by a susceptibility to recurrent spontaneous seizures. It occurs in 0.5-1% of the population, and 60% of cases start in childhood.
Diagnosis can be difficult. The epilepsies comprise many different seizure types and syndromes, with different prognoses for responding to medication, resolving spontaneously, or for associated co-morbidities.
A child’s history should alert GPs to the possibility of epilepsy and, in particular, certain epileptic syndromes common or rare, but crucial not to miss.
The clinical history and age of the child are vital in aiding the diagnosis (see below).
Eyewitness reports are valuable. Capturing the event on mobile devices can be very helpful. History taking and video reviews should focus on:
- onset of the event, although it is often not seen. Identify whether there was a trigger
- how the seizure evolves
- degree of unresponsiveness/loss of awareness
- any colour change and when it occurred
- limb movement
- postictal behaviour
Epilepsies are not usually missed - GPs are more likely to forget other possibilities. Fewer than 25 per cent of all children in whom epilepsy is considered will actually have epilepsy. Conversely, the false positive diagnosis rate can be as high as 15%. The box lists differential diagnoses for 'fits, faints, and funny turns'.
|Clinical features to diagnose or rule out epilepsy|
|Features making an epileptic seizure more likely:||Features making an epileptic seizure less likely:|
|None of these features are absolute, and there are plenty of exceptions. Diagnosis should not be based on the presence or absence of individual features.|
Epilepsies at different ages
Early childhood (up to 4 years old)
Be aware of serious early infantile onset epileptic encephalopathies (EIEE). EIEE may present any time from birth through early childhood, and is characterised by a severe seizure disorder, often infantile spasms, a very abnormal EEG, and developmental plateau, delay, or regression in the first year of life. Early treatment may lead to better developmental outcomes.
- Infantile spasms. (West syndrome). Onset of EIEE is at around 4 months of age, with spasms in clusters. Parents may report colic or suspected reflux, or lack of visual interest, or social interaction. There may be a characteristic chaotic EEG (hypsarrhythmia,) and cortical abnormalities on brain imaging.
- Febrile convulsions. These occur in about 5% of children and are not epilepsy. However all children with complicated febrile convulsions (duration longer than 15 minutes, multiple seizures in 24 hours, or focal features) should be referred to a paediatrician to consider underlying structural lesions, or the onset of a genetic epilepsy/EIEE (for example, Dravet syndrome).
Middle childhood (4-10 years)
Characterised by more benign conditions, with good developmental and educational outcomes, and greater likelihood of spontaneous resolution.
- Childhood absence epilepsy. This makes up 12% of epilepsies, and is usually drug responsive. Children have sudden behavioural arrest and impaired consciousness lasting seconds, with immediate resumption of activity at offset. Other features include jerks of the eyelids and the corner of the mouth, automatisms, head-droop, or relaxation of grip.
- Benign epilepsy with centrotemporal spikes (BECTS). This is the most common idiopathic epilepsy, with onset between 5 and 8 years of age. Seizures are usually clonic, with paraesthesia affecting one side of the face, bulbar muscles, and upper limb. They occur on waking, are infrequent, and may not require treatment.
Later childhood epilepsies (from 10 years)
Now termed genetic generalised epilepsies, these life-long epilepsy syndromes often emerge after 10 years of age, and include idiopathic generalised epilepsy, juvenile myoclonic epilepsy, and juvenile absence epilepsy.
- Juvenile myoclonic epilepsy (JME). This makes up about 10% of all epilepsies and is characterised by myoclonic jerks while awake (unlike hypnopompic/hypnogogic sleep jerks), usually in the early morning. Triggers include sleep deprivation, stress, and menses. Later, infrequent generalised tonic-clonic seizures emerge. JME is easy to diagnose, but also easy to miss. Diagnosis is often delayed until the first generalised tonic-clonic seizure and even then can be misdiagnosed as idiopathic generalised epilepsy. The wrong diagnosis may lead to the wrong drug being prescribed, aggravating the myoclonic jerks.
All children, young people, and adults with a recent onset suspected seizure should be seen within 2 weeks by a specialist to avoid misdiagnosis, as well as to ensure early diagnosis and treatment if appropriate. In your referral letter, outline the clinical features and, if possible, the perinatal history, family history, and school progress.
All children with epilepsy should be under the care of a GP and a consultant paediatrician with expertise in epilepsies. Children under 2 years of age, and all with drug resistant epilepsy will also see a consultant paediatric neurologist.
The diagnosis of epilepsy is made on the history. The paediatrician may arrange investigations, including an ECG (differential diagnosis cardiac), EEG, and MRI brain scan (in all children under 2 years of age, and those with suspected focality or drug resistant epilepsy). An EEG does not make or refute the diagnosis of epilepsy (there is a 60% false negative rate on the first EEG).
Other investigations, including blood, urine, and CSF, to exclude other diagnoses or to determine an underlying cause, may be requested at the discretion of the specialist. More recently, genetic evaluation of children with EIEE and drug resistant epilepsy is revealing an expanding list of copy number variants on array comparative genomic hybridisation (CGH) and genes in association with EIEE.
Anti-epileptic drugs are the mainstay of treatment. However in 20-25% of cases, epilepsy is drug resistant (defined as a failure of two appropriately chosen and used drugs). All these children should see a paediatric neurologist and be considered for the ketogenic diet, epilepsy surgery evaluation, and vagus nerve stimulation therapy.
Rescue medication (more recently, usually buccal midazolam) may be recommended for children with prolonged seizures (more than 5 minutes). All children should have a treatment plan.
Treatment of comorbidities is of great importance in children, including cerebral palsy, learning difficulties, behavioural problems, autism, attention deficit hyperactivity disorder, and mood disorder.
|Differential diagnoses of paroxysmal events|
|Age group||Differential diagnoses|
|Toddlers and pre-schoolers||
|Do not miss cardiac clues, such as a sudden drop to the ground, pallor, or cyanosis at onset. In epilepsy, pallor and cyanosis are late and non-specific. Breath holding, reflex anoxic attacks, and faints may be followed by true epileptic phenomena (jerking), secondary to cerebral hypoxia. This list is not exhaustive. There are many more causes of 'funny turns', such as the movement disorders.|
- Description of the seizure is the main diagnostic tool
- All children with suspected epilepsy should be seen by a paediatrician
- Do not miss infantile spasms
- Ask about early morning jerks in teenagers
- Consider cardiac causes and, if suspected, refer promptly
- Treatment of epilepsy includes anti-epileptic drugs, ketogenic diet, epilepsy surgery, and vagus nerve stimulation therapy
- National Institute for Health and Care Excellence. Epilepsies: diagnosis and management. CG137. January 2012 (revised 2016).
- Epilepsy Action https://www.epilepsy.org.uk/info/treatment/epilepsy-surgery/children
- International League Against Epilepsy http://www.ilae.org
- British Paediatric Neurology Association, Paediatric Epilepsy Training Courses. https://www.bpna.org.uk/pet
- Dr Sophia Varadkar is a Consultant paediatric neurologist in London
- Dr Pinki Munot is a Consultant paediatric neurologist in London